S&P GSCI Copper Spot Index GAS-GARCH Student T Volatility Analysis
Volatility prediction for Tuesday, July 21st, 2026
1 Day
18.65%
decreased by 0.12%
1 Week
18.74%
decreased by 0.03%
1 Month
19.07%
increased by 0.30%
Analysis last updated: Monday, July 20, 2026 at 11:09 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Jul 17, 2026Model Insight
With persistence 0.993, volatility shocks have a half-life of 92 trading days (~0.4 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate. Returns follow a Student-t distribution with v = 5.66 degrees of freedom, capturing fatter tails than a normal distribution.
𝑓
GAS-GARCH-T Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 2.2740 | 4.90*** |
α ARCH Response to squared shocks | 0.0435 | 37.17*** |
β GARCH Volatility persistence | 0.9925 | 578.72*** |
ν DF Student-t tail thickness | 5.6616 | 6.68*** |
Persistence:
0.993
Half-life:
92 days
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